Automatic oiling arrangement of a die-casting machine

ABSTRACT

On oiling the sliding area existing between the inner surface of a sleeve and the outer surface of a plunger tip, an oil supply to said surface can be made automatically by injecting a lubricant onto the sliding surface during the time of the movement of the plunger tip away from the platen, thus eliminating manual oiling operation.

United States Patent Jimi et al.

[ Oct. 23, 1973 AUTOMATIC OILING ARRANGEMENT OF A DIE-CASTING MACHINE Inventors: Yuji Jimi; Takahiko Takeshima,

both ,of Ube, Japan Assignees: Ube Industries, Ltd.,

Yamaguchi-ken; Nippon Light Metal Company, Ltd., Tokyo, both of Japan; part interest to each Filed: Dec. 31, 1971 Appl. No.: 207,359

Foreign Application Priority Data Dec. 15, 1970 Japan 45/124740 US. Cl. 184/5, 184/55 R, 425/107 Int. Cl. Fl6n 7/00 Field of Search 425/107; 184/18,

184/24, 5, 7 D, 7 E, 6.28, 55 A, 55 R; 92/156,157,158

[56] References Cited UNITED STATES PATENTS 3,110,931 11/1963 Kadel 184/24 X 3,544,355 12/1970 3,581,845 6/1971 Van Nederynen 184]? D FOREIGN PATENTS OR APPLlCATlONS 1,446,922 6/1966 France 425/107 Primary Examiner-Manuel A. Antonakas AttorneyPaul & Paul [57] ABSTRACT On oiling the sliding area existing between the inner surface of a sleeve and the outer surface of a plunger tip, an oil supply to said surface can be made automatically by injecting a lubricant onto the sliding surface during the time of the movement of the plunger tip away from the platen, thus eliminating manual oiling operation.

4 Claims, 9 Drawing Figures PATENTEDUBI 23 I975 SHEET 1 [1F 4 INVENTORS. JIMI IKO TAKESHIMA YUJI TAKAH ATTORNEYS miminocrzamn 3.767.012 SHEET 2 0F 4 INVENTORS. YUJI Jl Ml TAKAHIKO TAKESHIMA ATTORNEYS.

PAIENIED um 23 I975 SHEET 30F 4 INVENTORS.

YUJI JIMI TAKAHIKO TAKESHIMA ATTORNEYS PAIENIEDnmea ma 3.767012 SHEEI U, UF 4 /X; 1/ 45 I5 34 K35 INVENTORS YUJI JIMI TAKAHIKO TAKESHIMA BY MHQWK/ ATTORNEYS.

AUTOMATIC OILING ARRANGEMENT OF A DIE-CASTING MACHINE BACKGROUND OF THE INVENTION This invention is related to an automatic oiling apparatus for the sliding area between the inner surface of a sleeve and the outer surface of a plunger tip. Especially such oiling takes place during the time that the plunger tip is moving away from the platen, but no oiling takes place during the time that the plunger tip is approaching the platen.

When die-casting an aluminum or its alloy, the need for oiling the area of sliding between the sleeve and the plunger tip is commonly recognized and is necessary in order to maintain smooth operation under high temperatures of around 300C or more. This oiling has been commonly carried out manually up to now. After the completion of die-casting, the moving platen with a pattern die is parted from the stationary die by means of a suitable mechanism such as an oil cylinder. In this case, the pattern of the die is filled with a molded diecast product. After removing the die-cast product from the pattern die, and also after the completion of the movement of the plunger away from the platen up to its starting position manual oiling can be commenced by inserting an oily cloth by hand into the inner bore of the sleeve, passing through the space between both dies. And generally this operation takes place at every cycle of the die-casting operation, or once every two cycles.

An oil spray apparatus is employed for spraying the lubricant onto the inner surface of the sleeve by inserting the apparatus into the inner bore of the sleeve passing through the space between both dies. In the case where this type of oiling is employed, there must be some fonn of protection from damage to the operators hand, but even in such cases it there will be almost no difference in the quality of the oiling from the case of manual oiling.

SUMMARY This invention is related to an automatic apparatus for oiling the surface of a sleeve by a mechanical oiling apparatus, oiling of which takes place by a lubricant passing through an oil conduit provided within the plunger in every cycle of die-casting, and also is done during the movement of the plunger away from the platen after the die-casting operation is completed.

In our invention, an automatic oiling arrangement mounted on the plunger of a die-casting machine is characterized by, a plunger provided with an oil inlet, two or more oil ejection nozzles are disposed to said plunger in the vicinity of the end face of the tip of said plunger, in an arrangement directed towards the inner surface to be oiled, said nozzles are communicated to said inlet via a conduit running through said plunger so that the lubricant is supplied to said nozzles, lubricant is supplied to said oil inlet from a given oil supply source via flexible connectors.

Owing to the oiling by means of our arrangement, a lubricant can be applied to the inner surface of the sleeve adjacent to the faces of the plunger tip, so that perfect lubrication can be expected thereat, and furthermore more uniform lubrication is generated over the whole length of the inner surface of the sleeve.

Due to the oiling being done mechanically the dangerous manual oiling operation can be completely eliminated. Furthermore, the oiling is accomplished within one cycle of the die-casting, so the additional time required in manual oiling is completely eliminated.

Another important characteristic of this invention is that the oiling takes place with moistured lubricant, which enables more even and reliable oiling to be maintained than with manual oiling. In addition to this, the operational rate of a die-casting machine can be enhanced due to better oiling on the surface of the sleeve, which is continued until the plunger returns to its starting position. Therefore there is no lost time required for oiling. This means that where this inventional embodiment for die-casting machine is applied, a higher speed die-casting machine can be designed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an entire arrangement of the main part of a die-casting machine with partial omission in the disposition that the metal substance is being poured,

FIG. 2 shows the same view as FIG. 1, but shows the situation where a metal substance has been forcibly molded into the die-cast pattern,

FIG. 3 shows the same view as FIG. 2, but shows the state where the die-opening operation is completed,

FIG. 4 shows a cross sectional view of an embodiment of the plunger and the sleeve,

FIG. 5 shows a cross-sectional view which is taken through line V-V in FIG. 4,

FIG. 6 shows a cross-sectional view of another embodiment with a nozzle together with a compressed air jet hole,

FIG. 7 shows a cross-sectional view which is taken through line VII-Vll on FIG. 6;

FIG. 8 shows a cross-sectional view of another embodiment with a movable inner rod, and shows the state where the plunger and a sleeve are moving towards the platen,

FIG. 9 shows a cross-sectional view of the same embodiment of FIG. 8, and shows the state where the plunger and sleeve are moving away from the platen.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 3, show the typical operation cycle of the die-casting molding process. A die mounting platen 51 is firmly mounted on the machine bed, on which platen an injection sleeve 1 is secured in its corresponding hole. A stationary die 52 is located on the bed in con tact with the platen 51 also. Within sleeve 1, a plunger tip 5 is mounted slidably along the longitudinal axis. The plunger body 3 and the plunger tip 5, coupling 6, piston rod 7 with piston 8 are integrally connected in an axial alignment. The piston cylinder housing 19 is also secured onto the machine bed in an axial alignment with the members 3, 5 and 6.

A pattern die 53, which is cooperative with the stationary die 52, is mounted on a movable platen 54 guided by four horizontal guide bars 55, which are fixedly supported by the die-mounting platen 51. The injecting sleeve 1 is provided with an upper radial opening 2 formed near its outer end, through which a prescribed amount of molten substance is poured into the interior of the sleeve, as shown in FIG. 1, to the illustrated level 58.

After introduction of the melted metal into the sleeve 1, liquid under pressure is introduced into the cylinder 19 through the inlet 21 so that the piston 8 is pushed towards the platen 51. By this pushing, the arrangement finally reaches the disposition shown in FIG. 2. After solidification of the molten metal into a casted product 59, the cast product 59 can be separated from the surface of the pattern die 53 by the displacement of the moving platen 54 from the platen 51 along the guide rail (not shown) of the bed (see FIG. 3).

The solid die-cast product 59 is removed from the pattern of the pattern die 53. At the same time manual oiling can be applied onto the inner surface of said injecting sleeve 1 by using a proper oiling apparatus, such as an oil injector, passing through the space between the surfaces of pattern die 53 and stationary die 52, after the plunger 3 has resumed its initial disposition. This movement of said plunger 3 away from the platen 51 can be induced by introducing liquid under pressure into the cylinder 19 through the inlet 20.

As mentioned already, the arrangement of this invention is related to an automatic process of an oiling operation to be applied to the above-mentioned inner surface of the sleeve 1, which arrangement will be explained in detail with reference to FIGS. 4 to 7.

In FIG. 4, the plunger body 3 is provided with the plunger tip 5 and the spacer 4, the front part of which is screwed into the hole of said plunger tip 5, and also the rear part of which is screwed into the hole of the plunger 3. Within the plunger 3 a long oil conduit 9 is provided longitudinally at its center.

This long oil conduit 9, through which a lubricant can flow, is connected to the oil pump 17 through the oil inlet 10 positioned on the rear side of conduit 9, to a flexible oil hose 16 and solenoid valve 18, as shown in FIG. 1.

Near the top part of the spacer 4, manyoil injection nozzles 14 are provided, and the center line of the nozzle 14 is inclined forwardly from the radial. The nozzles 14 are arranged at equal distances on the surface of the spacer 4, and the number of nozzles are greater than two, sometimes four or eight per one spacer 4. Within the spacer 4, an oil way 13 is provided, so that it can be connected to said nozzle 14, and also connected to the ring like oil way 12. Under such construction, it can be seen that if oil, at a pressure of about 1 kglcm is forced into the inlet 10, then the oil passing through the long oil conduit 9, ring like oil way 12, oil way 13 and nozzle 14 can be sprayed onto the inner surface of the sleeve 1, as is shown by 15 in FIG. 4.

This spraying is effected during the time that the plunger 3 moves from the position nearest the platen 51 to the position farthest from the platen 51. Thus lubrication of the inner surface of the sleeve 1 can be effectively carried out by moving the plunger tip 5 over the whole length of inner surface of the sleeve 1, and by spraying the inner surface just behind the plunger tip 5. Such oil spraying control can be done by means of a four way solenoid valve 18 arranged at the midportion of a flexible oil hose 16, which is operated in synchronism with the two way solenoid valve (not shown within drawings) for the cylinder 19. In the arrangement as constructed above, as soon as the plunger 3begins to move away from the platen 51, i.e., return movement, the oil spraying onto the inner surface of the sleeve 1 is initiated. Such oil spraying is continued until the plunger 3 is reached its initial position. But in the steps of the operation shown in FIGS. 1 and 2, no oiling is applied.

Another embodiment, shown in FIG. 6, has an improved plunger and improved oil spraying apparatus. A plunger body 3 is provided with two separate conduits along its axis. One conduit 9 is for the lubricant and the other conduit 27 is for compressed air.

Many air outlet holes 26, provided on the block 22, and arrange in the vicinity of the plunger tip 5, are drilled radially onto the surface of the block 22, and their axis is so arranged as to be at a tilted angle b" from the radial. An oil supply hole 25 which is part of the injection nozzle 14 is also provided on said block 22, but said hole 25 is in the side of the air outlet hole 26 at its end portion, and the axis of the hole 25 is sharply tilted by an angle a from the axis of hole 26, so that the high speed flow of compressed air through the air outlet hole 26 will be able to create a fine spray of oil, flowing from the hole 25.

The hole 26 is connected with, an air conduit 27 provided within the plunger body 3, through a hole 23 provided in the block 22 and a cylindrical room 29 of said block 24. The cylindrical room 29 is connected with an air inlet 28 provided on the plunger body 3 through a long air conduit 27.

The hole 25 is connected with a tubular room 30 in the block 24, and also with a long oil conduit 9. The blocks 22 and 24 are secured to the plunger body 3 by means of a bolt 31. And the connection between the plunger tip 5 and the plunger body 3'can be made by the screwed portion of the plunger tip 5.

The low pressure oil, at about 1 kg/cm, flowing out from the hole 25 can be convertedinto a very fine spray by the effect of the high speed air jet from the air outlet hole 26. The spray can be directed peripherally, and sprayed onto the inner surface of the sleeve 1 in the direction of the tilted angle b from the radial. The proper oil pressure for this use is about 3 to 4 kg/cni. This condition can provide more uniform and better distribution of spray onto the inner surface of the sleeve l, because it has to traverse a longer passageway to the inner surface than in the case where it is sprayed radially.

Furthermore, the direction of this spraying onto the inner surface of the sleeve 1 is almost tangential to the peripheral surface, so the lubricant sprayed onto the inner surface of the sleeve 1 per one nozzle is widely spread.

The third embodiment, shown in FIG. 8, has an improved plunger body. This body is provided with a plunger 33 which has a long control cylindrical bore, and with an opening 40 at its side, and a plunger tip 35 with a central hole is coupled to the plunger 33 by a screw. An inner rod 34 is slidably arranged within the central hole of the tip 35, and a enlarged top part 36 is arranged at the end of the rod 34, and on the opposite end of the inner rod 34, a piston 37 is fixed which cooperates with the cylindrical bore of the plunger 33. Many oil ejecting holes 45 are provided on the surface at the part just under the enlarged head 36 of the inner rod 34. This ejecting hole 45 is connected to the central oil conduit 39' which is drilled longitudinally on the inner rod 34. The opposite end of the conduit 39 is connected to the oil inlet 10, and the oil inlet 10 is allowed to move freely within the opening 40. Within the cylinder 38, two inlets 41 and 42 are provided on opposite sides of the piston 37, and a-liquid under pressure can be inserted into any room, which is defined by the cylinder 38 and the piston 37, through either of the inlets When the tip 5 is moving toward the platen 51, the

piston 37 is positioned at its extreme backward position by the high pressure liquid which is supplied into the room of cylinder 37 in FIG. 8 through inlet 41, which is directly connected to the inlet 21 of piston cylinder 19, as shown in FIG. 1.

The inlet 42 is also directly connected to the inlet 20 in the same manner as mentioned above. So the insertion of the pressure liquid through the inlet 21 causes the movement of the plunger 3 toward the platen 51, by the liquid flowing into the cylinder through the inlet 41, this means that the piston 37 is forced to move so that the enlarged head 36 can be forced against the front surface of the plunger tip 35. Because the enlarged head 36 is provided on the top end of inner rod 34, this part will stop the movement of inner rod 34 because of the end of the central hole of the plunger-tip 35, thus restricting the movement of the inner rod 34. This condition is shown in FIG. 8.

When the flow of the pressure liquid from the inlet 21 is transferred to the inlet 20, this causes the plunger 33 to move toward the platen 51 and also to cause the liquid to be inserted through the inlet 34. This means that the inner rod 34 is pushed so as to project from the surface of the plunger 33, and finally the nozzle 45 becomes exposed to the outside, but such position is in close vicinity to the front surface of the plunger tip 35, but outside of it. So if the pressured lubricant is inserted into the central oil conduit 39 through the inlet 10, then the spray of the lubricant can be obtained. As can be seen from FIG. 9, hole 45 is situated near the center portion of sleeve 1, so the condition of spray of the lubricant should be fine and uniform due to the fact that the distance between the hole 45 and the inner surface of the sleeve 1 to be lubricated is fairly large.

This arrangement provides enhanced lubrication in high speed die-casting, which requires better lubrication than in the case of the low, speed die-casting. Furthermore, thus lubricating system can lubricate the inner surface of the center hole of the stationary die 52, in addition to the front end portion of the sleeve 1.

Furthermore, if necessary, a two position lubricating arrangement can be provided, one at the front of the side surface of the plunger tip, and the other at the back of the opposite surface of the plunger tip. This means that move perfect lubrication can be expected than any of the embodiments mentioned previously.

What is claimed is:

1. Automatic lubrication means for die-casting machine comprising, in combination:

a. a movable plunger body having a compressed air inlet and a lubricant inlet;

b. a plunger tip secured to said plunger body;

c. said tip having a forward end face and a rearward end face;

d. a sleeve receiving said plunger tip and plunger body, the forward position of said plunger body forming a space between said body and said sleeve;

e. at least two compressed air jet holes disposed on said forward portion of said plunger body, and said air jet holes being directed toward the space between said plunger body and the inner surface of said sleeve;

f. at least two lubricant ejection nozzles disposed on said forward portion of said plunger body and in communication with said air jet holes for forming a spray lubricant;

g. first conduit means extending through said plunger body connecting said air jet holes to said compressed air inlet;

h. second conduit means extending through said plunger body connecting said lubricant ejection nozzles with said lubricant inlet;

i. a first flexible connector connecting said air inlet to a compressed air supply source; and

j. a second flexible connector connecting said lubricant inlet to a lubricant supply source.

2. Apparatus according to claim 1 characterized in that:

a. said air jet holes are directed at an angle relative to the radial for increasing the effective spray distance from said jet holes to said sleeve surface.

3. Automatic lubrication means for die-casting machine comprising, in combination:

a. a movable cylindrical plunger body having a compressed air inlet and a lubrication inlet;

b. a cylindrical plunger tip having a stem portion secured to said plunger body, said tip having a forward end face, and an annular rearward end face disposed at the forward end of said stern portion;

c. an annular valve block surrounding said stem portion between said rearward end face of said tip and said plunger body, said valve block moving with said plunger body;

d. a cylindrical sleeve receiving said plunger tip, valve block and plunger body, said valve block forming an annular space between said block and the inner surface of said sleeve;

e. at least two compressed air jet holes disposed on said valve block, said air jet holes being directed toward the annular space between said valve block and the inner surface of said sleeve;

f. at least two lubricant ejection nozzles disposed on i said valve block in communication with said air jet holes for forming a spray lubricant;

g. first conduit means extending through said plunger body connecting said jet holes to said compressed air inlet;

-h. second conduit means extending through said plunger body connecting said lubricant ejection nozzles with said lubrication inlet;

i. a first flexible connector for connecting said air inlet to a compressed air supply source; and

j. a second flexible connector for connecting said lubricant inlet to a lubricant supply source.

4. Apparatus according to claim 3 characterized in that:

a. said air jet holes are directed at an angle relative to the radial for increasing the effective spray distance from said jet holes to said sleeve surface.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, Dated Oct. 23, 1973 Yuji Jimi and Takahiko Takeshima Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Filing date should read December 13, 1971 Signed and sealed this 17th day of September 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents USCOMM-DC 60376-P69 & u,s. GOVERNMENT PRINTING OFFICE: 1969 0-366-331,

FORM PC4050 (10-69) 

1. Automatic lubrication means for die-casting machine comprising, in combination: a. a movable plunger body having a compressed air inlet and a lubricant inlet; b. a plunger tip secured to said plunger body; c. said tip having a forward end face and a rearward end face; d. a sleeve receiving said plunger tip and plunger body, the forward position of said plunger body forming a space between said body and said sleeve; e. at least two compressed air jet holes disposed on said forward portion of said plunger body, and said air jet holes being directed toward the space between said plunger body and the inner surface of said sleeve; f. at least two lubricant ejection nozzles disposed on said forward portion of said plunger body and in communication with said air jet holes for forming a spray lubricant; g. first conduit means extending through said plunger body connecting said air jet holes to said compressed air inlet; h. second conduit means extending through said plunger body connecting said lubricant ejection nozzles with said lubricant inlet; i. a first flexible connector connecting said air inlet to a compressed air supply source; and j. a second flexible connector connecting said lubricant inlet to a lubricant supply source.
 2. Apparatus according to claim 1 characterized in that: a. said air jet holes are directed at an angle relative to the radial for increasing the effective spray distance from said jet holes to said sleeve surface.
 3. Automatic lubrication means for die-casting machine comprising, in combination: a. a movable cylindrical plunger body having a compressed air inlet and a lubrication inlet; b. a cylindrical plunger tip having a stem portion secured to said plunger body, said tip having a forward end face, and an annular rearward end face disposed at the forward end of said stem portion; c. an annular valve block surrounding said stem portion between said rearward end face of said tip and said plunger body, said valve block moving with said plunger body; d. a cylindrical sleeve receiving said plunger tip, valve block and plunger body, said valve block forming an annular space between said block and the inner surface of said sleeve; e. at least two compressed air jet holes disposed on said valve block, said air jet holes being directed toward the annular space between said valve block and the inner surface of said sleeve; f. at least two lubricant ejection nozzles disposed on said valve block in communication with said air jet holes for forming a spray lubricant; g. first conduit means extending through said plunger body connecting said jet holes to said compressed air inlet; h. second conduit means extending through said plunger body connecting said lubricAnt ejection nozzles with said lubrication inlet; i. a first flexible connector for connecting said air inlet to a compressed air supply source; and j. a second flexible connector for connecting said lubricant inlet to a lubricant supply source.
 4. Apparatus according to claim 3 characterized in that: a. said air jet holes are directed at an angle relative to the radial for increasing the effective spray distance from said jet holes to said sleeve surface. 